Words of which William Shakespeare was the only recorded user, at some point, according to the Oxford English Dictionary:

• bepray
• bragless
• compulsative
• conceptious
• confineless
• continuantly
• correctioner
• disliken
• exceptless
• exsufflicate
• foxship
• insultment
• oathable
• offendress
• omittance
• overgreen
• overstink
• questant
• razorable
• successantly
• thoughten
• uprighteously
• wenchless

In Inventing English, Stanford literary historian Seth Lerer credits him with inventing nearly 6,000 new words.